The OEM rotors are made in Brazil and have poor metallurgy.
When they are subjected to high heat on the track the cracks will extend rapidlly. The rotors can also dissentegrate.
A rotor that dissentigrates at speed will take out the tire, wheel and body work and worse; may make the car uncontrollable and cause a shunt.
You can either install cheap new ones, consider them disposable and replace them after every 1 or 2 DE's
Buy replacement ones with better metallurgy, have them Cryo'd and stress relieved and get 3 X's the life.
I recommend and prefer the latter. It's really a horse-a-piece economically. I just feel better with the better rotors on the car and I have better things to do than changing rotors every other weekend.
I just replaced mine and they looked better than that. Subdriver posted pictures of how far he lets his go before replacement - it looked kinda scary to me, but I have no experience to base that on.
A bunch of the T1 guys go with the NAPA rotors. The one I just got are made in Canada - no idea about the metallurgy. Total cost $126 for all four including our repressive sales tax (8%). Not bad considering a set of pads is around $300.
I am interested in recommendations for better rotors, where to get them cryo'd, and the total cost of the operation. If 3X life is a reasonable expectation it may be worth the investment.
NAPA also sells cross drilled rotors for $49 each, I have no idea if they are any good. Anyone try these with aggressive pads?